I encounter a variant of this all the time in modeling projects at my day job, due to the fear of beginning an unknown process (in my case modeling).

Our clients often say things like, "We are not going to start modeling until "x" is completed."

To which I respond: "I'm not leaving my driveway, until all the lights are green."

It usually produces a chuckle, and helps everyone realize that we won't get anywhere sitting around waiting for the stars to align.